Sources told CBS 11 News that, shortly after the murders of the McLellands, Williams allegedly threatened county employees. While not elaborating on the nature of the threat or how it was received, the source told CBS 11 News that it included “demands” that had to be met at a “certain time on a certain date.”

Late on Saturday, investigators served a search warrant on a storage unit in Seagoville. Sources told CBS 11 News that the storage unit was rented out to Williams. Investigators pulled out a white Ford Crown Victoria vehicle from the storage unit. The car matches the description of a vehicle that was spotted near the McLelland home on the night of the murders.

FBI searching the home of former Kaufman Justice of the Peace Eric Williams in connection with the murders of Mike and Cynthia McLelland and Mark Hasse. (credit: CBS 11 News)

Sources also told CBS 11 News that 20 weapons were found inside of the storage unit. Federal investigators are now conducting ballistic tests on the guns.

Federal, state and local investigators had already executed a search warrant at Williams’ home and at his in-laws’ house on Friday. And authorities previously questioned Williams and tested him for gunpowder following the murder of Hasse in January, and then again after the March murders of McLelland and his wife.

Earlier this month, the CBS 11 News I-Team reported that Williams had a history with both McLelland and Hasse. The two prosecuted and secured a conviction against him in 2012 for burglary and theft by a public servant. Surveillance cameras caught Williams taking computer equipment from a county building. As part of his appeal, Williams claimed that McLelland and Hasse did not like him.

(credit: CBS 11 News)

Williams told CBS 11 News reporter Mireya Villareal that he had no involvement in the murders of Hasse or the McLellands. “My heart goes out to all the families that have been affected by this tragedy, and especially the people that work at the courthouse,” he said. Williams was not seen Friday during the warrant searches.

The manager of a nearby liquor shop said that investigators had been in the area for two weeks, often using his parking lot as a set-up point. Ray Rubio said that he was told, “They were here to monitor the area. Nothing to be alarmed about. But you”ll see cars here.”